Liver - Extramedullary Hematopoiesis
comment:Extramedullary hematopoiesis is unexpected in adult rodents and is typically associated with pathologic conditions. It is distinguished from inflammatory cell infiltrates by the presence of nucleated erythrocytes, immature granulocytes, and/or undifferentiated progenitor cells in the absence of associated hepatocellular necrosis. Clusters of erythroid cells are present in Figure 1 and Figure 2 (arrows). It is most often seen in animals treated with a toxicant and may be associated with hepatocellular degeneration, pigment deposition, and/or fatty change ( Figure 2 ). A megakaryocyte is present in Figure 2 (arrowhead). Multiple perivascular cellular accumulations in Figure 3 and Figure 4 consist predominantly of developing granulocytes.
recommendation:Whenever present, extramedullary hematopoiesis should be diagnosed and graded. Examination of bone marrow, lymph node, and spleen sections may show a correlation with extramedullary hematopoiesis in the liver. The types of cells involved (e.g., erythroid, granulocytic, mixed) should be indicated in the pathology narrative if they can be identified.
related links:Adrenal Gland - Extramedullary Hematpoiesis
Spleen - Extramedullary Hematopoiesis
Eustis SL, Boorman GA, Harada T, Popp JA. 1990. Liver. In: Pathology of the Fischer Rat (Boorman GA, Eustis SL, Elwell MR, Montgomery CA, MacKenzie WF, eds). Academic Press, San Diego, 71-94.
Harada T, Enomoto A, Boorman GA, Maronpot RR. 1999. Liver and gallbladder. In: Pathology of the Mouse: Reference and Atlas (Maronpot RR, Boorman GA, Gaul BW, eds). Cache River Press, Vienna, IL, 119-183. Abstract: http://www.cacheriverpress.com/books/pathmouse.htm
National Toxicology Program. 2010. NTP TR-558. Toxicology and Carcinogenesis Studies of 3,3',4,4'-Tetrachloroazobenzene (TCAB) (CAS No. 14047-09-7) in Harlan Sprague-Dawley Rats and B6C3F1 Mice (Gavage Studies). NTP, Research Triangle Park, NC. Full Text: http://ntp.niehs.nih.gov/ntp/htdocs/LT_rpts/TR558.pdf
National Toxicology Program. 2010. NTP TR-559. Toxicology and Carcinogenesis Studies of 2,3',4,4',5-Pentachlorobiphenyl (PCB 118) (CAS No. 31508-00-6) in Female Harlan Sprague-Dawley Rats (Gavage Studies). NTP, Research Triangle Park, NC. Full Text: http://ntp.niehs.nih.gov/ntp/htdocs/LT_rpts/TR559.pdf
Thoolen B, Maronpot RR, Harada T, Nyska A, Rousseaux C, Nolte T, Malarkey D, Kaufmann W, Kutter K, Deschl U, Nakae D, Gregson R, Winlove M, Brix A, Singl B, Belpoggi F, Ward JM. 2010. Hepatobiliary lesion nomenclature and diagnostic criteria for lesions in rats and mice (INHAND). Toxicol Pathol 38:5S-81S. Full Text: http://tpx.sagepub.com/content/38/7_suppl/5S.full
Web page last updated on: January 05, 2015